Osteopontin is involved in migration of eosinophils in asthma

• Published in: Clinical and experimental allergy Vol. 39; no. 8; pp. 1152 - 1159
• Main Authors: Takahashi, A., Kurokawa, M., Konno, S., Ito, K., Kon, S., Ashino, S., Nishimura, T., Uede, T., Hizawa, N., Huang, S-K, Nishimura, M.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01.08.2009; Blackwell
• Subjects: Adult; Aged; Animals; Antibodies - immunology; Antigen-Antibody Reactions; asthma; Asthma - immunology; Asthma - pathology; Biological and medical sciences; Bronchial Hyperreactivity - immunology; Bronchoalveolar Lavage Fluid - immunology; Cell Movement - immunology; Chronic obstructive pulmonary disease, asthma; Cytokines - analysis; Disease Models, Animal; eosinophil; Eosinophils - immunology; Female; Fundamental and applied biological sciences. Psychology; Fundamental immunology; Humans; Lung Neoplasms - immunology; Lung Neoplasms - pathology; Lung Neoplasms - surgery; Male; Medical sciences; Mice; Mice, Inbred BALB C; Middle Aged; migration; osteopontin; Osteopontin - immunology; Pneumology; Lung disease; Immunology; Respiratory disease; Granulocyte; Osteopontin; migration; Bronchus disease; Obstructive pulmonary disease; Eosinophil; Cell migration; Asthma
• ISSN: 0954-7894; 1365-2222
• DOI: 10.1111/j.1365-2222.2009.03249.x

Summary Background Osteopontin (OPN) is an extracellular matrix protein with a wide range of functions, and is involved in various inflammatory diseases. However, the role of OPN in eosinophilic airway inflammation is unclear. Objective To elucidate the role of OPN in eosinophilic airway inflammation. Methods OPN protein levels in induced sputum from asthmatic patients and healthy controls were measured. Eosinophil migration assays were performed in the presence or absence of OPN, a blocking antibody (Ab) recognizing its integrin‐binding domain (2K1) and an anti‐integrin α4 Ab (P1H4). In the mouse asthma model, the levels of eosinophilia were examined in bronchoalveolar lavage fluids (BALFs) from ovalbumin (OVA)‐sensitized and ‐challenged mice with or without administration of an Ab (M5) corresponding to human 2K1. Results Levels of OPN in induced sputum were significantly higher in asthmatic patients when compared with healthy controls. In addition, levels of OPN were correlated with the percentage of sputum eosinophils. OPN induced significant migration of human eosinophils and this effect was inhibited by 2K1 and P1H4. M5 significantly attenuated OVA‐induced eosinophilia in BALFs. Conclusion These results indicate that OPN plays a role in the migration of eosinophils into the airways and may be involved in the pathogenesis of asthma.